Move the extracted firmware file to the root of the USB (not in a folder). Flash: Turn off the TV. Plug the USB into the TV's USB port. Press and hold the Power Button on the TV panel. Plug in the power cord while holding the button.
These files typically contain a MstarUpgrade.bin file or similar. Installation Process Download CV628H B42 1366x768 Sony Normal (Seedha) part2 rar
The ".part2.rar" extension means the full firmware was too large for a single upload. Move the extracted firmware file to the root